Variable speed power transmission mechanism



July 5,' v1958- 'IFI AHAYEs 2,123,006

VARIABLE SPEED POWER TRANSMISSION MECHANISM BY M ATToRNr-:YS

July 5, Igftb.A F, A HAYES V2,23,006

VARIABLE SPEED POWER TRANSMISSION MECHANISM Filed June 18, 1932 ll Sheets-Sheet 2 INVENTOR BY ATTORNEYS lF. A. HAYES July 5, '1938.

' VARIABLE SPEED POWER TRANSMISSION MECHANISM Filed June 18, 1932 l1 Sheets-Sheet 5 INVENTOR BY M ATTORNEYS July 5, 1938. F. Aj HAYES VARIABLE 'SPEED POWER TRANSMISSION MECHANISM ll Sheets-Sheet V4 Filed June' 18, 1952 .R. K .m Wm m. 4 V N TM n, M R l' O T T AW /r 2.@ F

July 5,k 1938. F. A. HAYI-:s

VARIABLE SPEED POWER TRANSMSSION MECHANISM Filed June 18, 1932 l1 Shee'cs-SheerI 5 BY ula ATTORNEYS i A aow, 4Com, *KMA/Mw v July 5, 1938.y j v F. A. HAYES'A 2,123,006

` l VARIABLE' SPEED vPOWER 'TRANSMISSION MECHANISM y Filed June 1s, 1932 11 sheets-sheet e l INVENTQR BY A ATToRNEYs lJuly 5, 193s.

' Filed June 18, 1932 11 sheets-sheet 7 e: .ooo w i s V Nm s l V n A ON l s l if. m t r Y 7// 6: "SIRI, 1 B4 WIIJ/ ||l r 1 8N -//1 S Q l S IM l n: Mn s N: E gw 7 um 4 f r Q we mm? .emv f l //w// A .New- U T f S mw: H E:

July 5, 1938. F. A. HAYES y 2,123,006 -I VARIABLE SPEED POWER TRANSMISSION MEcHANIsM 4 Filed June 18, 1932 ll Sheets-Sheet 8 v A l INVENTOR hmm/k. www EY ATTORNEYS July 5, 1938. F. A. HAYES 2,123,006

VARIABLE SPEED POWER IANSMISSION MECHANISM Filed June 18, 1932 All Sheets-Sheet 9 p lNvENToR BY w1 ATTORNEYS vJuly 5, 193s. F. A. HAYES l 2,123,006

VARI-ABLE.) SPEED POWER TRANSMISSION MECHANISM ATTORNEYS July 5, 1938. F A, HAYES 2,123,006

VARIABLE SPEED POWER TRANSMISSION MECHANISM Filed Jupe 1s, 1932 11 sheets-sheet 11 `Patented July 5, 19318A UNITED N STATES PATENT OFFICE MECHANI Frank A. Hayes, Middletown, N. J.

Application June 18, 1932, Serial No. 618,054

In Great Britain August 19, 1931 32 Claims.

I This invention relates to variablespeed power transmission mechanisms of the friction type, particularly friction transmissions in which power is transmitted from a driving shaft or other member to a driven shaft or other member through the instrumentality of friction disks and interposed friction rollers cooperating therewith. According to one feature -of the invention it relates to mechanisms in which the roller centers are all approximately `or exactly in the same transverse plane. Transmission mechanisms of this latter type have been proposed heretofore, but the prior constructions have all had the serious disadvantage that a moving thrust bearing is required to carry the pressure needed between the disks and rollers. If the mechanism is designed for maximum power capacity, using hard steel as the friction material (i. e., making the rollerseand disks of hard steel) the pressures and rotation speeds necessary for maximum capacity are very high, and the balls in the aforesaid thrust bearing must be proportionately large, in some cases nearly if not quite aslarge as the rollers. 'I'his has led to various designs in which v two sets of rollers are employed, spaced axially apart and connected to operate in parallel as regards power transmission; but this results in increased complication and greater bulk, making the mechanism relatively long, which is in many cases objectionable. ject of the invention is to provide a compact mechanism of large capacity in proportion to its bulk. Another object is to provide a transmission mechanism possessing the simplicity of the type having a single set of rollers but having also the great advantage of the parallel or duplex type, in which the driving pressures are all selfcontained and taken by stress in` theoperating parts themselves, thus making the aforesaid thrust bearing unnecessary. To these ends I use twosets of rollers, but instead of arranging them in axially spaced planes I locate them in the same plane, and what would be the middle disk the two end disks. The result is that the disk` and-roller assembly is only about half `as long,

Accordingly one ob- (Cl. 'I4-200) axially, as in prior constructions having two sets of rollers.

Another object of the invention is/to provide simple and effective means for automatic equa1- ization' of load between the rollers of a set com- 5 posed of two rollers, and between two such sets in a duplex or parallel type of transmission mechanism.

A further object is to provide simple and effective means for producing and controlling speed-ratio changes in transmissions of the type in which the disks are toroidally grooved and precession of the rollers is brought about by tilting the roller axes.

Another object is to provide a simple and convenient mounting for rollers of the tilting type just referred to.

A still further object is to provide a control system for use when the transmission mechanism is employed in an automobile between the engine and the driving wheels of the car, which is operable from the accelerator pedal to give low engine-speed and correspondingly high fuel economy under ordinary driving conditions 4but with high engine speed and correspondingly rapid acceleration of the car available at all times.

Themanner in which these and other objects are attained by the present invention will be more readilyunderstood from a description of the preferred embodiment. This embodiment, designed f or transmitting power from the motor to the driving wheels of an automobile, is illustrated in the accompanying drawings, in which:

Fig. 1 isv a central longitudinal section.

Fig. 2 is a sectional plan view on line 2 2 of Fig. 1.

Figs. 3, 4, 5 and 6 are cross sections on lines 3 3, 4 4, 5 5, and 6 6, respectively, in'Fig. 1, looking in the directions of the arrows.

Fig. 7 is a cross section on line 1 1 of Fig. 6, showing in elevation lthe rockers for two of the roller carriers, and the cage in which the carriers are mounted.

Fig. 8 is a view in elevation, looking from the 4right in Fig. 1, of the cage in which the two sets of rollers are supported.

Fig. 9 is a side view of the cage, from the leftof Fig. 8.

Fig. 10 is a side `view of one of the roller-car- 50 riers and the roller mounted therein.

Fig. 11 is a detail sectional view on line Il ll of Fig. 1.

Fig. 12 is a diagrammatic section illustrating the principle of the invention. For lthe sake of I clearness the disks in this gure are shown widely spaced axially. y

Fig. 13 is a verticalsection illustrating a roller system in which the rollers are supported by a ball and socket mounting instead of by carriers and rockers.

Fig. 14 is a sectional plan view on line I4I4 of Fig. 13.

Fig. 15 is an elevation of the roller supports, taken from the right in Fig. 13.

Fig. 16 is an elevation (from the right in Fig. 13) of the annulus or ring which tilts the rollers to produce change of speed ratio.

Fig. 17 is a perspective view of the equalizing member shown in Figs. 13 and 14.

Fig. 18 is a sectional plan view, taken about on the plane of the disk axis, illustrating another embodiment of the invention, in which the disks or races and the sets of rollers are spaced apart axially.

Fig. 19 is a detail section on line I9-I9 of Fig. 18.

Fig. 20 is a cross section on line 29-20 of Fig. 18, showing manual means for rocking the rockers, which support the roller carriers, to initiate precession of the rollers.

Fig. 21 is a detail section on line 2I-2I of Fig. 20.

Fig. 22 is a detail section on line 22-22 of Fig. 18.

Fig. 23 is a detail sectional plan view taken on a plane indicated by line 23--23 of Fig. 20.

Fig. 24 is a plan view of the controller crank and indicator shown in side elevation in Fig. 20.

Fig. 25 is a detail section on line 25-25 of Fig. 22. l

Fig. 26is a detail section on line 26--26 of Fig. 20, showing the offsetting of the sockets in the rockers, to incline the axes of precession of the roller and their carriers to the planes of the disks.

Referring to Figs. 1, 2 and 12, four toroidally grooved coaxial disks o r races are shown, designated I5, I6, I1, I8, with interposed rollers I9, 2li, 2i, 22. Disks I5 and I6 are in the same plane,

and disks I1 and I8 are similarly arranged in a` plane spaced axially from the first two. Disks I and I1 constitute an inner, and disks I6 and I8 an outer race element or member.v Rollers I9, 20 ,cooperate with disks I5 and I8, and assuming that disk I5 is the driving disk (rotated by any suitable means, as for example shaft 23, on which disk I5 is keyed), and assuming also that the rollers can revolve in planetary fashion around the disk axis a-a and that disk I8 is held stationary or non-rotatable, it will be seen that the rollers will revolve about the disk axis at anangular speed depending, other conditions being constant, upon the angle of the rollers to the disk axis or the planes of the parallel disks. Similarly, if the rollers are non-planetary and disk I8- rotatable, the latter will be rotated at a speed also depending upon the angular position of the rollers. Thus,`with the rollers in the positions shown in full lines lin Fig. 12, the speed of disk I8 will be low relative to the speed of disk I5, butas the rollers are turned to the dotted line positions I9a, 20a, the speed of diskv I8 relative to the speed of disk I5 will increase. In general the speed of disk I8 is represented by the formula N=n(R/r), in which N is the speed of disk I8 in revolutions per unit of time, n the speed of disk I5, R (Fig. 12) the radius from the disk axis a.a to the point of contact of the rollers on disk I5, and r the radius to the point of contact of the `aiaaooe rollers on disk I8. Rollers/l I and 22 cooperate in the same Way with disks I1 and I6.

From inspection of Fig. 12 it will be clear that disks I5 and I1 may rotate at the same speed, in which case, with non-planetary rollers, disks I6 and I8 may be drivenl at vthe same or at diiferent speeds, depending upon the relative angular positions of the rollers. On the other hand, if the rollers are planetary they must be set at the same angles to the disks since otherwise they would revolve, around the disk axis, at different speeds and hence would collide. It will also be seen that disks I6 and I8 may be the driving disks and disks I5 and I1 the driven disks; and that if the rollers are planetary they may be revolved to drive disks I6 and I8 if the disks I5 and I1 are stationary, or vice versa. One or another of the three elements, namely, the race element composed of disks I5-I1, the race element composed 4oi disks I6-I8, and the roller element composed of the two connected sets of rollers, must be stai raceways are rigidly fixed in the encircling drum 24 which is connected by a spider or cone 25 to a driven shaft 26. Disks I6, I8 thus form, in effect, an internally grooved ring concentric with disks I5, I1. At one end of the apparatus'the two-part driving shaft 23 isl mounted in a ball bearing 21 carried by the housing 28 and its cupped other end is supported by a ball bearing 29 on a stud 30 mounted in the adjoining end of the driven shaft 26. A certain minimum frictional engagement of the disks and rollers is obtained by one or more spring washers 3| between disk I1 and the flange 3Ia on the cup. The rollers are nonplanetary, and hence the speed of the driven shaft depends upon the ratio R/r (Fig. 12) and therefore upon the angular positions of the rollers, as will be readily understood. v

Rollers I9, 20, Fig. l, are mounted on ball bearings, whose inner races are mounted on studs 36 fixed in carriers 31, 38, and rollers 2|, 22 (Fig. 2)/ are similarly mounted in like carriers 39, 40. One carrier, say 38, is shown in elevation in Fig. 10. The carriers are mounted by vball and socket joints at their ends in rockers 4I, 42, 43, 44 (Figs. 6 and '7), having trunnions pivotally mounted in a supporting cage 45 (Figs. 8 and 9) having arms 46 extending outwardly between races I5 and I6 into connection with a. supporting plate 41, Figs. 1 and 3. The arms 46 are toothed at their outer endsas indicated in Fig. 9, to engage 4teeth in the 'central aperture in plate 41, which is xed between the two parts of the housing. Rotary disapplication Serial No. 361,031 now Patent No. 1,865,102, issued- June 28, 1932. For this purpose the rockers are provided with arms 50, 51,52, 53 (Figs. 6 and 7) extending radiallyrinward and connected by inclined pins 54, 55, l56, 51, to inclined recesses in a centrally apertured circular plate 58 encircling the shaft 23 and carried by tar'ms 59 extending out between disks I5 and I 6 into connection with a vcontrol ring 60 (Figs. 1

10 and 2) so that when'the ring is rotated the rocklers 4I, 42, 43, 44 are rocked in the cage 45, therebyv shifting or displacing equally all the rollerv* carriers simultaneously and bodily in line with their axes of precession (which pass through the centers of the balls by which the carriers are supported) and thus causing the rollers to swing, or precess, on the said axes toward a higher or lower speed ratio position according tothe direction of the displacement of the carriers, as explained in my prior Patent 1,865,102 referred to above. In accordance with the principle explained in the patent just mentioned the axes of precession are slightly inclined to the planes of the disks (for example by suitable location of the balls on the rockers or the sockets in the carriers) to cause the rollers, as they precess, to return to the position of equilibrium. So long as the axes on which the rollers rotate (not those on which they precess) intersect the axis of the disks, the rollers 3Q have no tendency to precess. When, however,

the rollers are displaced in line with their axesof precession by rocking the supporting rockers the roller axes do not intersect the disk axis but pass the same on one sideA or another and precession at once begins; but as the precession continues the roller axes are swung back into inter section with the disk axis (becauseof the inclinations of the precession axes) and precession then ceases. The position of intersection is conven- 4o iently termedthe equilibrium position.

To prevent all possibility of the rollers precessing too far in either direction the cage is provided with stops 84, Figs. '1 and 2, arranged to be engaged by the roller carriers before the rollers 45 themselves can pass oil the disks or come into rubbing contact with any stationary part.

The control ring 60, Figs'. 1 and 2, is connected by a link 65, Fig. 5, to a finger 66 on a rock shaft 61 which is connected by an arm 68 and rod 69 to a skirted control piston 10 ina control cylinder 1|. A spring 12 urges the piston toward the position at which the control ring and rollers .are in the low speed position, that is, with the rollers `at angles such as are shown in Figs. 1 and 2. The cylinder is connected by a pipe lla to a pipe 14 leading from a pump (which may be the lubricating pump, not shown, driven by the engine 15) supplying iluid under pressure, and hence the rightward movement of the control piston, and consequently the speed ratio position of the transmission rollers, depend primarily upon the speed of the engine, which in turn dependsother conditions being the same, upon the opening of the throttle 15a by actuation of the accelerator pedal 14a which is connected to the throttleby a rod 15e. In the side of the control cylinder 1I is a port 1lb connected to a drain pipe 1|c discharging into the sump or other'receptacle (not shown) from which' the pressure fluid is pumped. This drain pipe is provided with a valve 11d, and the skirt oi piston 10 has an opening 10a which registers with the drain port 1lb when the piston is in a low speed position as indicated in the figure. Pipe 11a is also connected by pipe 16 to a cylinder 11 containing a spring-actuated piston 18 connected to a arm 19 which operates the usual clutch, which may be between the engine and the transmission mechanism or between the latterand the propeller shaft which is connected4 to the driving wheels through the 5 diiferential. The spring in the cylinder tends to disengage the clutch, and does so unless the oil pressure back oi the piston is s'uicient to overcome the spring.- With the engine idling and the valve 'Hd in the position shown in full lines the110 oil from pipe 14 escapes freely to the sump by way of ports 10a, 1lb and pipe 1 I e and hence the pressure is insuiiicientto advance the control pistn or engage the clutch but as the driverspeeds up the engine theclutch piston 18 is gradually ad- 15 vanced and the car starts, the control piston 10 remaining in the low speed position. As soon as the car starts, further speeding up the engine increases the oil pressure suiliciently to advance the control piston, thereby causing the transmis- 20 sion rollers to precess to a higher speed ratio position. Up to a certain point this precession will continue (to higher and higher speed ratio positions) as long as the engine `continues to increase in speed and therefore continues to ad- 26 Vance the control piston 10; but when the latter ceases to advance, the precession of the rollers brings the roller axes (i. e., the axes on which the rollers rotate) again into intersection with the disk axis and the precession then ceases. If at any time the load reaction exceeds the torque of the engine the latter is slowed down and the oil pressure is correspondingly decreased, permitting the rollers to precess to lower speed-ratio positions until the engine torque and load reaction; are again in balance. Other conditions being the same, this decrease of speed-ratio can only be prevented by increasing the throttle opening, thereby keeping up the speed of the engine.

As the operator turns the control valve lld 40 thereby uncovering the by-pass channel or passage 80, more and more oil passes through pipe 1| c to the sump. and less pressure is developed on control piston 10, thereby decreasing the tendency of the rollers to take higher speed-ratio 45 positions asz the engine speed increases, and when -th e valve is turned far enough, say tov the dotted line position, the pressure on clutch piston 18 is insuiiicient to hold theV clutch engaged and the engine is disconnected from the transmission 50 mechanism. 'I'his adjustment oi the valve is useful for starting and warming up" the engine, for purposes of test and repair, and also provides for/adjustment of the relation of engine speed to car speed at the will of the operator. At the 55 same timel the control piston remains in the low speed-ratio position ready for starting the car when the valve is again turned to the running position.

Pipe 1i a is also connected by pipe 'He to a port 60 Hf in avalve cylinder 11g having a drain 1|h` leading to theA sump. In the cylinder is a sliding sleeve valve 1li provided with a port Hic and connected by a rod 15b to the accelerator pedal 14a in such manner that when the pedal is in 65 the position at which the throttle is closed as far as permitted by the stop 15e the port 1Ik is at the left of port, 1|f and the latter is therefore closed.

Control cylinder 1I also has a port 11m, con-v 70 nected by pipe 1in to a port'TIp in valve cylinder 'Iig so that. as the sleeve 1li is advanced by depression of the accelerator pedal, port 1|1c in the sleeve can be brought into register with said port 11p in the valve cylinder. Control piston 75 i 10 has a port 1|r which opens port 1Im 'when the piston reaches a certain `position in its ad- I vance or rightward movement. 'I'he purpose and operation of these devices are as follows.

In the'flrst place; the gear ratio at the differ I ential of the car, that is, between the driving shaft or propeller shaft and the driving wheels,

is made low, for example 2 to 1; which means cylinder 1I is located not at the point (in the rightward path of the piston) at which the speed ratio of the transmission mechanism has its highest value, but at the point at which, with due regard to the low gear-ratio at the differential' and the power of the engine, the engine can drive the car with the maximum velocity.

With the control devices in the positions shown in Fig. 5, the car standing still and the engine idling, to start the car the operator depresses the accelerator pedal in the usual way. 'Ihe clutch is engaged at once, and as the car velocity increases, the operator depresses the pedal fully, thereby giving the throttle its widest opening and bringing port 1llc of valve 1li into register with port 1li. The inertia of the car, however, keeps the engine speed down. As the car velocity increases, the engine speed increases and the control piston 10 advances, with the result that the car accelerates rapidly.v Desiring to attain the maximum car velocity the operator keeps lthe pedal depressed. If, then, the load and road conditions do not prevent (by keeping the engine speed down), the advancing control piston 10 opens port 1Im, permitting enough oil to escape through pipe 1in, port 11p and registering port 11k to prevent further advance of the piston, thereby keeping the transmission mechanism at the speed ratio which, with the gear ratio at the differential and the power of the engine, will enable the engine to drive the car at maximum velocity. If the velocity thus attained is too high the operator simply lets the pedal rise, as he naturally would. The rst eiect of this is to move the valve sleeve 1li rightwardly far enough to close port 1Ip so that oil can no longer escape through pipe 1in, whereupon the control piston `begins to 'advance and is now in the overdrive" range. This has the effect of operating the car at maximum engine torque but reduced engine speed, resulting in high economy of operation. If the pull of the engine at the maximum over-drive is sufficient to drive the car faster than desired, the operator continues to raise the accelerator pedal in the usual way, thus closing the throttle until the desired velocity is attained. If the pull of the engine is not enough at the maximum over-drive ratio to drive the car at the desired velocity the operator depresses the pedal again far enough to partially open port 1 i p, thus reducing the pressure in control cylinder 1I andljallowing piston 10 to recede until the proper ratio for the desired velocity is obtained.

The car is now traveling at the desired velocity.

At the same time the throttle is practically wide open and the engine is therefore operating at a high eiiiciency. Coming to an up-grade and desiring to maintain his speed, `the voperator depresses the\accelerator pedal, thereby opening more or less the port Hp in valve cylinder 11g through port 1|1c in sleeve 1li. The resulting decrease of pressure behind the control piston permits the latter to drop back, with corresponding decrease of the speed ratio of the transmission and increase of engine speed and pull on the driving wheels. If the engine then begins to slow down, the resulting decrease of oil pressure lets the piston move back still farther and open port 10a still farther. rI'his farther relief'of the pressure (through valve 1|d) permits the piston to move back farther still, making it still easier for the engineto carry the load. If the engine does not maintain the desired car velocity, with the accelerator pedal fully depressed and port 1lp therefore Wide open, the continued decrease of engine speed may permit the control piston to move back far enough to close port 1Im. The transmission mechanism isnow below the overdrive range, and with increasing load resistance the piston may move back to the extreme low speed position, at which the maximum pull is delivered to the driving wheels. If at any time before port 1Im is closed by the leftward movement of the piston and the car velocity increases too much, the operator simply lets the accelerator pedal rise, thereby restricting port 11k: more or less, or even closing it entirely, and causing in- Icreased pressure behind the control piston and corresponding increase "of speed ratio, decrease of engine speed, and corresponding decrease of car velocity.

From the' foregoing it will be seen that by proper design of the parts, location and shape of the various ports, etc., the movement of the acceleratorpedal necessary to control the speed of the car by opening and closing the port 1lp can be made to have only relatively slight eiect on the throttle opening, which means that under vaverage driving conditions the throttle can be practically wide open; and this without any change in the accustomed use of the accelerator n by the driver. That is, to increase the speed of the car the pedal is depressed, thus opening port 11p and thereby decreasing the pressure on the control piston and permitting the engine speed to increase (and with it the car velocity) without increasing the speed ratio of the transmission mechanism. While to decrease the speed of the car it is only necessary to let the pedal rise, thus closing port 1Ip and thereby causing the transmission mechanism to change up so fast in the over-drive range that the engine speed, and car velocity, are kept down. At any time, however,

if the load resistance is so highrthat port 1lm` in the control cylinder is closed by the receding piston and transmission mechanism is then in a low speed ratio and, port 1lb being wide open, a relatively high engine speed, depending on-the 4adjustment of valve 1Id, can be attained without causing the piston to advance. u

To stop the car it is .only necessary to let the accelerator pedal rise and apply the brakes. Sudden stops may stall the engine, with the control piston in an advanced position and ports 1lb and 1|p both closed, in which case the clutch would remain engaged by reason of the oil trapped in the fluid pressure system, and the engine could not be started again. To obviate this difilculty a release pedal 15f is provided which may be positioned for operation by the left foot, in place of thevusual clutch pedal. Then before attempt is made to start the engine this pedal is depressed, causing its pin 15g to lift the accelerator pedal and thereby shift the valve sleeve 1li rightwardly, bringing port 1Ik into register with the port Tlf. This gives the entrapped oil an outlet, `permitting the spring in the clutch cylin der to disengage the clutch, and the spring in the control cylinder to retract the control piston to the low speed position. The relief pedal may l be the brake pedal. In either case, whether .the

relief pedal is in place of the clutch pedal or is the brake pedal, the operator in stopping theto the point at which port 'IIk is in register with port Tlf.

'I'he amount of power transmissible to the load.

on the driven shaftv 26 depends, otherthings be- '.Each groove deepens From study of the construeing the same, upon the friction between the rollers and the disks, with the result that overload may cause slippage, with resulting wear and damage. This may be obviated by making the pressure of the disks or. races on the rollers great enough; but in that case the pressure is 'unnecessarily high for lighter loads. `Accordingly the present invention includes a novel torque loading construction by which the pressure between the rollers and disk depends upon the load resistance, increasing as the latter increases, and vice versa, though not necessarily in a strictly linear manner. For this purpose the inner part 23a of the two-part driving shaft 23, Fig. 1, is journaled at its outer end in the outer part 23h which is equipped with a cup 85 having teeth in its edge cooperating with teeth on the periphery of la cam member or collar 86 rotatable and axially movable on the inner shaft-part 23a. 'Ihreaded on the journal of the latter is a ball thrust-bearing 81, and between the collar 86 and the disk I5 are three or more balls 88 working in cam grooves or depressions 89 in the collar (see Figs. 3 and l1) and similar depressions 90 in thedisk. gradually from its ends to its central portion. tion described it will be seen that if there is overload on the mechanism the shaft 23h will run ahead of disks I5 and |'I and shaft 23a. As this occurs the balls 88 are rolled into shallower parts of the cooperating depressions or recesses, thus urging disk I5 toward `the right, and collar 85 (and with it the shaft 23a and disk II) toward the left, thereby increasing the pressure of disks I5 and I8 on rollers I9, 20, and the pressure of disks I6, II on rollers 2|, 22. The friction of these parts on each other is thus increased so that no slip of one on the other can occur. It will be observed that the operation described is entirely automatic. Ii at any time the load reaction on shaft 23h is decreased the lessened tendency of shaft 23a to lag permits the balls to roll back to deeper parts of the recesses, thereby decreasing the pressure exerted 'on thedisks and rollers. In this way the pressures of the parts on each other is always proportional tothe load and unnecessarily high stresses and losses. are avoided. It will also be observed that in the action described there is no rotary movement ,of disk I5 relative to disk I1, or vice versa.A ,This is a novel and advantageous feature, since such relative rotation would cause one set of rollers to drive the rigidly connected disks I6|8 at a different rate than the other set, with resulting slip and wear which would sooner or later cause serious damage. It is advantageous to have the endof the apparatus but it may be positioned at the other endif desired. The pressure-producing mechanism described in this paragraph is not claimed in the present application but is claimed pressure-producing mechanism at the driving.

function the plate moves axially in one direction or the other, and to permit the slight movement -necessary' a clearance is provided for the control ring 50, Fig. 2, on both sides of the same, and

the link 65, Figs. 1 and 2, is loosely connected to the ring or to the arm 66 or both, The plate 58 also effects equalization between the rollers of each set. In performing this function it'moves transversely. or radially of the disk axis. In this movement the plate; the arms 59, and the control ring tilt as a whole on the ball bearing 60a, Fig. 1, the balls of which work on ungrooved races.

Assuming vthat the driving shaft 23, Fig. 1, is rotating in the direction of the arrow, i. e., clockwise as viewed from the left, it will be seen `that the ring or disk assembly I6-I8 and driven shaft 26 will be rotated inthe opposite direction, which would drive thecar in the forward direction. To permit forward or reverse drive at will the gear system housed in the rear part of the casing-28 is provided, as illustrated in Figs. 1 and v4, comprising a gear 95splined on shaft 26 and on the 'countershaft |03 and connected by'sleeve |04 to gear |05 meshing with a reverse idler gear |06 which in turn meshes with gear |00, thus giving reverse drive.

The form of tneinvennon illustrated in Figs. 1 3

to 16 differs from the first in the mannerv in which the rollers are mounted and controlled. In this second form the rollers I I0, I I I are mount- .ed on ball bearings whose inner races, as |I2, constituting carriers forthe rollers, are supported by ball and socket joints on the radial arms H3, m of piste H5 (Fig. 15), wnicn'forms a iioating support for rollers IIO, I I I, and is ca' pable of slight rotary movement about a sleeve IIS carried by arms III extending outwardly through the annular space or gap between disks I5 and I6. Alongside of plate II5 is a similar plate II8, spaced from the first by a ball bearing IIS, having radial arms |20, |2| (at right angles to the arms H3, I l) on which rollers |22, |23, Fig. 14, are carried by ball and socket joints. Each plate is capable of slight radial movement in directions transverse or at right angles to its Y two roller-supporting arms.

Referring to Fig. 13, if the roller I|0 is tilted on an axis indicated by dotted line |25, coplanar with the disk axis, the roller will precess on an axis perpendicular to the plane of the figure and passing through,the center of the ball on which the roller is supported. Assuming that disk I5 is rotating counterclockwise as seen from the right, and that the roller is tilted counterclock- Wise as seen from the upper end of axis I25,`the roller will precess clockwise toward a higher speed 55 left or ,ratio position. Similarly, if the roller is tilted (on axis |25) in the other direction it will precess to a lower speed ratio position. For the purpose of tilting the rollers to bring about automatic and progressive or gradual 'change of speed ratio by precession in the manner just described, they are provided with.- axial stems or anns |26, |21, |28, |29, extending loosely into helical slots or grooves |30, I3I, |32, |33 formed in arc-shaped flanges |34, |35, |36, |31 on a ring |38 arranged between the disks I6 and I8. This ring is provided with a pair of arc-shaped arms |40, |4| whiclf extend out through the annular space between disks I5 and I 6 for connection with a suitable control ring 60a, which may be rotated by a crank pin 60h working in a radial slot 60e. Keeping in mind thecpnstruction just described,I it will be seen that if control ring 60a.' is given a slight rotary movement the roller stems, and with them the four rollers, will be tilted, some in 'one direction and some in the other, according to the direction in which theY ring was rotated, thereby causing the rollers to rock or precess toward higher or lower speed ratio positions, as the case may be.

Rotation of the ring |28 in the clockwise direction (as viewed from the left of Figs. 13 and 14) swings stem |26 of roller I|0 upwardly and the stem |21 of roller downwardly, thereby tilting the rollers correspondingly and causing the two to precess to higher-speed ratio positions.

As the roller ||0 precesses, its stem |26, Fig. 13,

moves clockwise in the helical groove |30, and

upon reference to Fig.' 16 it will be seen that since the groove has a righthand twist (relative to the axis 'of precession) `the movement of the stem therein swings the stem downwardly (in Fig. 13), thus tilting the stem and roller lback toward lthe position of equilibrium, in which position the axis of rotation of the roller intersects or is c oplanar 40 with the axis of the disks. 'As the precession continues the roller eventually reaches the full equilibrium position, and at that position its precession ceases, leaving the roller in a new, and

higher, speed ratio position.` Evidently the extent of this reverse tilt is in every case equal to the initial or forward tilt which caused the precession, and it will therefore be clear that the farther the roller is tilted to initiate theprecession the farther will the roller precess and the higher will be the new speed ratio. It is also evident that if the roller is in the extreme high e vor in any intermediate position between th highest and lowest, rotation of the control ring a in the lcounterclockwise direction as seen from the Fig. 13 will swing stem |28 down 'on its ball and thereby cause the roller to precess to a lower speed position. Upon reilection it will be clear that rotation of the control ring hes the same effect upon roller as upon roller ||0; 60 except that to cause precession of roller III from the low speed position of Fig. 13 to a higher position, arm |21 must be tilted downwardly, that is, away from the observer looking at the figure named. And of course rollers |22 and |28, Fig. 14,

operate in 'the same way as the other two.

The sleeve H6, which extends through the plates H5, H8, is provided at its ends with inwardly extending inclined or helical slots |50, engaged by radial pins IBI mounted in the plates IIS, ||8 with a smooth viit permitting the plates to move transversely to the disk axis as mentioned hereinbefore. The sleeve is non-rotatable but is capable of slight axial movement in both directions, and for this purpose the arms I|1 which support the sleeve are mounted to slide on studs |52v suitably fixed in any convenient stationary part. The sleeve constitutes an equalizing device and eiectsA automatic equalization of the load between'the 'sets of rollers and between the rollers of each set, as will now be described.

Suppose that in its precessional movement, say toward a higher speed ratio position,'rol1er, H0,

rig. 13, shoum run ahead of rouer nl. In such case it drives disk I8 faster 'than roller II I drives it, and hence roller tendsqto roll upwardly on the disk, toward the observer. At the same time roller I0 also tends to roll up on-the disk, toward the observer, since it is transmitting the larger share of the power and is subjected to the drag exerted on the disk by the other roller. Both rollers, therefore, roll upwardly on the disk, the plate H5, which carries the roller-supporting arms ||3,'||4, sliding on its pins I5I, Fig. 14. In such movement the stem |26 of rollerA I |0 swings upwardly on its end in groove |30 as a pivot. This is in fact a down-swing on its supporting ball;

- and remembering that such down-swing produces precession toward a lower speed position it will be seen that the roller precesses in that direction, and that as it does so the stem swings up on its ball support and brings the roller to equilibrium position. n At the same time. thevstem |21 also swings upwardly on its end in groove |3| as a pivot, which movement is in fact a down-swing on its supporting ball, and accordingly roller precesses to a higher speed position. The net result is that the two rollers take the same intermediate position, at whichl they drive disk I8 at the same speed. It will be observed that the ,roller-supporting plate I|5, which supports the rollers ||0, I||,Fig.13, fioats on the pins |5I, I5I, Fig. 14 (the pins shown in a horizontal position in Fig. 15), soas to be free to move transversely of the sleeve I6 and the axis of the disks or races ,in response to variations of the torque transmitted by any one of the rollers of the set composed of rollers H0, and that such transverse movement, causing precession or tilting of one roller on its axis of precession to a lower speed-ratio position, and the other to a higher speed-ratio position, serves to bring both rollers of the set to an intermediate position at which they transmit equal torque. Similarly, in the [other set, oating plate I`| 8 serves, by its transverse movement at right angles to the equalizing movement oi' plate H5, to adjust rollers |22, |23,

to positions at which they also transmit equal torque. Ineach case the ioating roller-supportv ing plate is normally centered, that is, with the.

disk axis.l When the roller supporting plate moves transversely of the axis of the disks or` `races the axes of rotation of the rollers carried by the plate are displaced so that these axes no longer pass through the disk axis, with the result that the rollers precess in the directions neces- 'sary to bring them to the speed-ratio position in ywhich they transmit equal torque.

Again, suppose one set of rollers takes a different speed ratio position from the other set, the lagging set, say I I0, |||,Figs. 13 and 14, will then have a slight planetary movement, counterclockwise as seen from the left of Fig'. 13. Stem |26 therefore swings down on the end in groove |30 as a pivot. This is equivalent to an up-swing of the stem on its ball support, and accordingly the roller precesses toward a higher speed ratio position. At the same time stem |21 swings up on its endin groove I3| as a pivot and hence roller .I I also precesses toward a higher position. Furiov ment the pins' |5| (Fig. 14) which extend from plate into the inclined or helical slots in sleeve |I6 exert a cammlng'effect on the sleeve which, since it can not rotate, is thereby shifted .5 axially toward the left in Fig. 14. This axial movement ofthe sleeve permits the pins ISI, Fig. 13, and plate ||8 `which carries the pins, to have a slight planetary movement also, but in the clockwise direction. This causes stems-|28, |29 to swing on their ends in grooves |32, |33 as pivots, and upon reflection it willbe seen that this will cause the two rollers to preeess to a slightly lower speed ratio position. The net result is that the two sets are brought to the same speedposition. It will be seen that equalization of the rollers of one or both sets may take place while the two sets are equalizing, and it will also be seen that the action is entirely automatic. This is a highly advantageous feature, as it takes care of considerable inaccuracy in the manufacture and fitting of the parts, which otherwise would have to be of the highest precision. Even then, very slight unequal wear* or the like would result in an unbalv anced condition which would cause further unequal wear, and so on, with the result that the mechanism would' in a relatively short time be seriously injured.

The equalizing method described hereinbefore `is not limited to mechanisms in which sets of be employed to advantage when the sets are spaced apart axially. An embodiment of this type is illustrated in Figs. 18 to 25 inclusive. In this construction thefdisks |65, |66 correspondin general to the disks -I 5, |1Jof Figs.' 1'v and 13, but are spaced apart to accommodate disk |61, which corresponds to disks I6, I8 arranged back to back. Disk |61 rotates on asleeve |68 encircling the shaft |69 and extending axially from a threearmed spider one arm of which is shown at |10, l Fig. 18, the spider being integral with .a transverse plate or diaphragm I1| xed solidly between the two parts |12, |13 of the transmission housing. On the right end of the sleeve |68 is splined |14. Disk |65 is rigidly connected to shaft |69, but disk |66 is slidably keyed to the shaft, so that by tightening nut |15 against the spring Washers |16 disk' |66 is urged leftwardly against vthe three rollers between the disk mentioned and the middle disk |61,-one of which rollers -is shown at I 11. At the same time the shaft |69 and disk |65 are drawn rightwardiy against the rollers |18.

Both sets of rollers are thus pressed against theV middle. disk to giveuthe necessary frictional engagemen't to drive the middle disk when shaft the 'driving element, l

V|69 and disks |65, |66 are or to rotate disks |65, |66 and shaft |69 when the middle disk is the driving element. In either case disk |61 is splined to the edge of a. drum |19vv which surrounds rollers |11 and is connected to shaft |80 in which the inner end of shaft |69 is mounted. Shaft has a flange |8| for connection with any'desired mechanism, for example a mechanism which is to drive, or be driven by, the transmission.

The transmission rollers |18 are mounted in carriers |85, Figs. 18 and 20, which are themselves rotatably supported byball and socket Joints in the rockers |86 pivoted on the spider |10,Fig. 18, and provided with inwardly extending arms |81 having ball ends engaging slots |88 in the terminal flange at the adjacent end-of an equalizer v sleeve |89 encircling'the shaft |69. This equalrollers are arranged in thesame plane but 'can' asimilar spider, one arm of whichis shown at4 izer sleeve is connectedby arms or spokes |90 toA an annulus or rim |9| (see also Fig. 22). The sleeve being rotatable about shaft |69l and inside of sleeve |68, it will be,seen that by giving the rim |9| a slight movement of rotation in either direction the rockers 86 will be rocked correspondingly on their pivots. This movement of the rockers will either shift the carriers in line with their axes of rotation in them about the axes on' which the rollers rotate, or both shift and tilt them, according to the angular relation of the arms .|81 to the ball and socket joints by which the carriers are mounted, as explained, in my copending applications Serial No. 361,031, filed May 7, 1929, now Patent No.

1,865,102, issued June 28,v 1932, and vSerial No.

590,360, led'April 29, 1932, now Patent No.

the rockers, or tilt pending with my present application. In any case the rollers preeess to a higher or lower speed ratio, according to the direction in which the sleeve |89 was rotated as described in my copending patents just mentioned. Preferably the axes of precession of the rollers and carriers are inclined tothe planes 'of the disk so that the extent of precession of the rollers and carriers will depend upon the amplitude of the yrocking movement imparted to the rockers, as explained in my copeiiding applications referred to. For this purpose the sockets in which the ball ends of the carriers aremounted may be voffset as indicated in Fig. .26, in which it will be observed that the upper socket is offset to the left and the lower to the right of the vertical center line `of the rocker |86. It will be understood that in Fig. 20 the upper socket of the rocker at the upper left of the figure is nearer the observer than is the lower socket of the same rocker, whereas the upper socket of the rocker at the upper right is farther from the observer than is its lower socket. Similarly the left hand socket of the lower rocker is nearer the observer than .is the right hand socket of that rocker.

The rollers |11 of the other set, Fig. 18, are

similarly mounted with their axes of precession inclined to the planes of the disks in 'a direction opposite to inclination of .the first set, and the arms |93 of their rockers |94 engage slots |95 in i, the flange or ring |96, Figs.` 18 and 19, splined in "l a fixed position on the adjacent end of the equal- 'izer sleeve. It-will therefore beseen that when the sleeve is rotated by `rim |9| as described in connection with the first set of rollers the carriers of the second set will be similarly actuated, causing like precession of the rollers.

The slots |88, |95 at the two ends of the equalizer sleeve |89 are inclined in opposite directions for the same purpose as are the similar slots |50 ln sleeve 6, Fig. 17,' that is to say', to provide automatic equalization of load between the sets of rollers. It will be understood that rotative movement of the sleeve |89 is intended to rock all the rockers equally, to cause equal precessional movement of the rollers to change the speed-ratio of the mechanism. Transverse or radial movement of either or both' ends of the sleeve causes differential rocking movement of one or more rockers to initiate equalizing precession'of the appropriate rollers of the respective set, as does transverse or radial movement of the plate 58, Figs. 1 and 2. Longitudinal or axial mov ent of the sleeve equalizes the load between the two sets of rollers, as does axial movement of plate 58, p just mentioned. In explanation of the equali'zing action between sets of rollers, let it be noted first that the frictional forces exerted on the rollers,

(ifiV when the transmission mechanism is driving a load, tends to revolve the rollers around the disk axis in planetary fashion, thereby taking up all the axial play or clearance which the roller carriers have with respect to their supporting rockers. If' (after this `play is taken up) allthe rollers are in the same speed-ratio position, then both sets drive the load at the same speed;.but nevertheless the aforesaid frictional forces constantly tend to shift the rollers farther in planetary fashion, which farther shift would, if it occurred,

position. Call this the leading set.y

cause precession of the rollers to a lower speedratio position. But this tendency is resisted by the control mechanism with which the sleeve is connected for actuation, that is, the rocker arms |81, |93, ring |9|, links |98, lever |99, etc., Fig.

20; hence, when the load is equally divided bey on the two sets are equalized, i. e., the forces "are in equilibrium, and there is no tendency for the sleeve to be cammed axially in one direction rather than in the other. some reason one set is in a higher speed-ratio Since it tends to drive the load faster than does the other or lagging set, the frictional forces due to load reaction are unbalanced and the rocker arms of one set therefore exert greater pressure on the equalizingsleevethan do the arms of the other set, with the result that the leading set can move in the` planetary manner in the direction ofthe frictional forces on it, thereby rocking its rockers and thus causing the arms of its rockers to cam the sleeve axially. The planetary movement just referred to causes the leading set of rollers to precess toward a lower speed-ratio position, and at the same time the axial movement of the sleeve swings the rocker arms of the other set (by the cam action of the inclined recesses engaging the latter arms) in the direction to cause precession of its rollers to a higher speed-ratio position. The net result is that the two sets come to an intermediate position at lwhich both drive the load at the same speed. At this position the load is equally divided between the two. Equalization among the rollers of a set in Figs. 2 and 20, for example, is in principle the same as between sets of rollers. Instead, however, of the sleeve being shifted axially it is shifted transversely, thereby causing differential precession of one or more rollers of the set. It will be observed that in Figs. 2, 18 and 20, the equalizing devicethe single floating ring or plate 58 in Fig. 2 and the floating sleeve |89 with its two recessed collars in Figs. 18 and .20-are capable oi' movement axially and transversely, so that equalization among the rollers of a set, and equalization beltween sets, can take place concurrently. Thus the sleeve c an tilt or move as a. whole transversely in any direction, with or without simultaneous movement axially. In any case the action is automatic and is effective within the limits of the precessional adjustment incident to the'axial play of the carriers with respect to their rockers. It will also be seen that the equalizing device functions, as such, only when there are on the rollers But suppose that for The ring |9| and equalizing sleeve |89 are rotated to bring about change of speed-ratio by a' control shaft 205 (described hereinafter) through a universal connection therewith. .For this purpose the ring is connected at opposite sides by links |98, Figs. 18, 20, and 22, to a bail |99, Fig. 23, the legs 200,of which are pivoted to ears 20| on a transverse scale beam lever 202 fulcrumed between its ends at 203 in the plate |1| and the end wall of the housing |13. It will be observed that in all positions of the lever 202 the bail can swing up or down (in Fig. 20) on its pivotal connection with the lever, that is, in a plane trans-Y verse to the lever, thus permitting the ring |9| and sleeve |89 to tilt up or down. Also, the links |98 areloosely connected to the ring and to the bail, as by means of the ball joints shown in Figs. 23 and 25, thus giving the sleeve universal freedom of movement, permitting it to move bodily in both axial directions, to move bodily in all radial directions, and to tilt at each end in every radial direction, without being materially resisted by the connection with links |98, bail |99 and lever 202. The sleeve is thus enabled' to perform in an efficient manner all the equalizing functions of sleeve I6, Fig. 13, and of disk 58, Fig. 2.

The`adjustment of lever 202 to bring about changes of speed ratio is effected by means of a threaded axially stationary control shaft 205, Figs. 20'and 21, working in a non-rotatable nut 206 having trunnions 201 extending into longitudinalslots 208 in the arms of a'yoke 209 pivoted at their lower ends to the adjacent end o f lever 202. Between the yoke and the bearing 2 |0 of shaft 205 is an expansion spring 2li. It will be seen in the construction described that when the shaft is rotated clockwise (as seen in Fig. 24) the nut and yoke are causedto descend under the influence of spring 2||, thereby rocking lever and bail |99 clockwise and causing the rollers to precess to a lower speed-ratio position. At all times the rollers are subjected to the reaction of the load which the mechanism is driving, tend Aing to shift the roller carriers in a direction toV cause precession to a lower speed-ratio. This reaction is exerted against and is resisted yonly by the tension of spring 2li, andwhen at any speed ratio position of the rollers and yoke 209 the reaction exceeds the spring tension the spring will yield and permit the yoke to rise and lever y1n the path f me lever 2oz as the latter is swinging to or toward a predetermined low speedratio position is a spring-raised button 2|5, Fig. 20, cooperating with an electrical contact 2|6 to close the same upon contact 2|1, these contacts 75 being in a normally closed circuit, represented by the wires 2 I8, which is associated orconnected in any suitable way with the power means, not shown, driving the transmission mechanism. For example, when the mechanism is driven by an electric motor, the contacts may be in the motor rollers have precessed into contact with the stops l10n, Illa, the lever 202 is rocked still farther.

On the control shaft bearing 2I0 is an index disk 220, Figs. 20 and 24, traversed by apointer 22| on the handV crank 222, which disk may be graduated to indicate a suitable number of speed ratio positions. A nut 223 on the control shaft, having a handle 224, serves tolock the shaft in any position of adjustment.

The spring 2li has the important function of limiting the input torque of the transmission,- since it is subjected to the load reaction, but its deflection corresponds at all times to the speedratio position of the rollers due tothe fact that the yoke 209, the position of which determines the maximum speed-ratio at a given instant, rises land compresses the spring as the tension of the latter is exceeded by the load reaction. Hence by proper choice of the spring and its initial tension the input torque can be limited to any desired value in all speed-ratio positions. For example, with a constant speed driving motor the horsepower taken by the transmission can be limited to a substantially constant value. 4

Having now particularly described and ascertained the nature of -my said invention and in what manner the same is to beperformed, I declare that what I claim is:

1. In a friction transmission'mechanism, in combination, a pair of axially spaced coaxial disks having inwardly facing toroidal grooves, a second pair of axially spaced coaxial disks having inwardly facing toroidal grooves, a set of` friction rollers arranged substantially in a plane transverse to the axis of the disks and cooperating with the grooves of the first pair of disks, a set of friction rollers larranged substantiallyin the same plane as the first set and, cooperating with the other pair of disks, supporting means for said rollers, and means for adjusting the rollers angularly with respect to said plane to vary the speed-ratio of the mechanism.

2. A friction transmission mechanism comprising an inner disk and an outer concentric disk encircling the first, an inner disk coaxialwith the first inner disk and a! second outer disk concentric With the second inner `disk and encir cling the same, the four disks having inwardly facing toroidal grooves; transmission rollers cooperating with the grooves in the first inner and the second outer disks and transmission rollers cooperating with the grooves in the-second inner vand the first outer disks; all said rollers being in substantially the same plane and mounted for angular adjustment relative to said plane to vary the speed ratio of the mechanism.

3. A friction transmission mechanism comprising a grooved inner race element, a grooved outer race-element encircling the inner raceelement and concentric therewith, a coaxial driv- I ing shaft connected with one of the race-elements to drive the same, two sets oi transmission rollers arranged in substantially the same plane between the race elements to drive the other race element from the driving element and mounted for angular adjustment to vary the speed ofthe driven disk element, and a driven shaft coaxial with the race elements and connected with the driven race element for actua- 10 tion thereby.

4. A friction transmission mechanism comprising a pair of coaxial internally grooved driving disks, and a pair of internally grooved driven disks concentric with the driving disks and encircling the same; a set of transmission rollers cooperating with one of the driving disks and a driven disk; a set of transmission rollers in substantially the same plane with fthe rst set cooperating with the other driving disk and the other driven disk; the rollers of both sets being mounted for angular adjustment relative to said plane to vary the speed ratio of the mechanism; and means extending between one of the driving disks and the encircling driven disk to eifect such adjustment of the rollers.

5. In a friction transmission mechanism, in combination, an inner race-member having toroidal grooves, anlouter race member encircling the same and having toroidal grooves. two

sets of.'v transmission rollers arranged in substantially the same planelto cooperate with said race elements and mounted for angular adjustment to vary the speed-ratio of the mechanism, and

means extending between the race elements from outside the same into connection with the rollers to vary their angular adjustment.

6. A friction transmission mechanism comprising a disk element composed of two coaxial grooved disks, a roller element composed of two connected sets of transmission rollers arranged in substantially the same plane and cooperating with the said disk element, and a disk element composed of coaxial grooved disks encircling the first disk element and cooperating with the roller with the equalizing member for converting axial movement of the latter intomovement of angular adjustment of both sets of rollers respectively in the same angular direction to bring both sets to'the same intermediate speed ratio position.

8. In -a variable speed friction transmission mechanism, in combination, a driving shaft, a driven shaft, and mechanism for driving the latter from the former, comprising coaxial torcidally grooved disks, four transmission rollers arranged in two sets cooperating with the grooves in the disks, carriers for the rollers, mounted for preiessional adjustment of the rollers to vary the speed-ratio of the mechanism, and actuating members connected with the carriers to 

